User:Dentren/Andean orogeny

The Andean orogeny is one of the worlds major mountain-building events and it has been going on ever since XXX million years ago in the XXX period. The mountain chain has not rised evenly and mountain bulding effects has acted unevenly along different sections. The Andean orogeny is largely a pruduct of the subduction processes at the South American Plate's western margin, subducton itself begun XXX years ago during the XXX period. The Andes is not the first mountain chain to build up in western South America, it was preceeded by the X X and X orogens althought the material of these mountains are now either part of South American Plate of have been recycled into earths interior by tectonic erosion.

The Andes mountains begun to rise XXX million years ago (mya) during the XXX period. The mountain chain did not rise evenly and